Cleaning machine



Nov. 8, 1949 J. F. MALSBARY ET AL 7,

'CLEANING MACHINE Filed Aug. 18, 1944 HVVENTURAL JOB F. MALSBARK WALTER W. TAYLOR.

ATTORNEY.

Patented Nov. 8, 1949 CLEANING MACHINE Job F. Malsbary and Walter W. Taylor, Oakland, Calif., assignors, by mesne assignments, to Malsbary Manufacturing Company, Oakland, Calif., a corporation of California Application August 18, 1944, Serial No. 549,973

2 Claims. (Cl. 299-84) The present invention relates to improvements in cleaning machines intended principally for use in connection with tanks, trucks, trailers, tractors, automobiles and various parts of engines and machinery. A cleaning machine of this type is illustrated in our Patent No. 2,295,228, granted on September 8, 1942.

The patented machine comprises in its principal features a coil with heating means for the same, a water tank, a solution tank, a high pressure pump drawing on both tanks and discharging into the coil under pressure, and a discharge hose connected to the coil and provided with a gun and nozzle at the free end thereof.

, This machine has been manufactured and operated successfully for a number of years. In the present invention it is proposed to provide an improvement in the feeding means for the coil.

We have discovered that where a dilute cleaning solution is fed through the pump, it has a tendency to produce a scale in the pump passages, to make the valves gummy and sticky, and to plug up passages and strainers so as to necessitate considerable repair work and servicing during the life of a pump.

We have attempted to remedy this condition by pumping an acid preparation through the pump, but we found by experience that such acid treatment is generally unsatisfactory for the reasons that it usually caused some damage to the working parts of the pump and particularly to the valves thereof. In fact, the remedy, in many cases, brought about a worse condition than that sought to be cured.

On the other hand we have found that if a cleaning solution is fed through a pump in concentrated form, it produces no such deleterious effect and that a concentrated solution may be fed through a pump for an extended period of time without producing any harmful effects.

The solution tank of our cleaning machine contains a cleaning solution in concentrated form, by which we mean a solution containing about one pound of powdered chemical to five or eight gallons of water.

When the concentrated solution is mixed with water in the pump, it is diluted substantially in the proportion of one to ten, so that the dilute solution contains about one pound of powdered chemical to fifty or eighty gallons of water. It is this dilute solution which produces the harmful effect in the pump passages.

It is proposed in our present invention to eliminate this source of trouble by feeding the concentrated solution directly to the coil, thus bypassing the main pump and preventing the passing of a dilute solution through the latter.

It is further proposed to provide a second auxiliary pump for pumping the concentrated solution directly into the coil and to provide suitable reaching the main pump.

means for preventing any dilute solution from And finally, we propose to arrange the second pump in such a manner that it is operated by the main pump so as to eliminate the necessity of providing a special power drive for the second pump.

Further objects and advantages of our invention will appear as the specification proceeds, and

the novel features of our improvements will be fully defined in the claims hereto attached.

The preferred form of our invention is illustrated in the accompanying drawing, the sole figure of which diagrammatically shows a complete cleaning machine made in accordance with the present invention.

While we have shown only the preferred form of our invention, it should be understood that various changes or modifications may be made within the scope of the claims hereto attached, :vithout departing from the spirit of the invenion.

Referring to the drawing in detail, our cleaning machine comprises, in its general features, a base I, a water tank 2, a solution tank 3, a water pump 4, a solution pump 5, a coil 6 and a discharge hose 7 having a gun 8 with a nozzle 9 at the end thereof.

The water tank 2 receives its supply of water from any suitable source through a pipe Ill and the water is maintained at a constant level by the float control indicated at I l.

The solution tank 3 also receives its water from the pipe l0 and may be filled to a predetermined height by means of a float control I2, a suitable valve, not shown, being provided to stop further flow, as the contents of the tank are drained out. A suitable cleaning chemical, preferably in powdered form, is mixed into the water to produce a concentrated solution of desired strength.

The water tank is connected to the pump intake l3 through a pipe M having a strainer [5 at the lower end thereof. The pump discharges through the control valve it into the pipe 9 l, which feeds into the upper end of the coil ii.

The control valve i6 is of conventional construction and serves as a pressure relief valve. It may be set to deliver the water to the pipe [1 at a desired pressure, say 300 pounds at the gauge 18, and to feed any excess liquid back to the suction pipe I 4 through a by-pass l9. one end of the sleeve to the other in order that The pipe I1 is additionally equipped with a conventional air dome 20, a check valve 2! preventing the return flow of the liquid, and a metering valve 22 allowing the exact amount of water passing into the coil and the coil pressure to be controlled. A second gauge 23, on the delivery side of the metering valve. indicates the pressure of the liquid in the coil which in the normal operation of the machine is considerably lower than the pump pressure.

The coil 6 is mounted in the housing 24 in such a manner that the liquid flows downward in the coil toward the heater 25, a suitable thermostat control 26 being provided at the lower end of the coil. Any other type of boiler may, of course, be substituted for the coil, without departing from the spirit of the present invention.

The lower end of the coil discharges into av pipe 21 having a shut-oil valve 28, and the latter pipe discharges into the hose 1 provided withthe gun 8 having a discharge nozzle 9 at the end thereof.

The heater is here shown as a gas heater and the details of the heater and the thermostat control are fully described in our Patent No. 2,295,228. They may be briefly described as comprising a main gas supply line 30 having a main valve 3!, a diaphragm housing 32, and the thermostat control 26.

The diaphragm housing is divided by a diaphragm into an upper chamber 33 and a lower chamber 34, which contains a valve in the pipe 30 operated by the diaphragm. The latter is punctured to allow of slow pressure exchange between the two chambers and is spring-pressed to normally close the valve, when the pressures in the chambers are balanced.

In operation, when the coil requires heat, the thermostat valve 26 opens, relieving the pressure in the upper chamber 33, and allowing the pressure in the lower chamber to open the valve and to admit gas to the burner 25. When the coil requires no more heat, the thermostat valve closes, allowing the pressures in the two chambers to equalize for closing the valve in the diaphragm housing and for reducing or stopping the flow of gas.

A conventional by-pass 35', controlled by a valve 36, feeds the pilot 3'! and the upper chamher is connected to the thermostat valve 26 through a pipe 38, the escaping gas passing through a pipe 39 to a second pilot 40.

The solution is fed directly into the pipe I! near the coil, that is, preferably between the metering valve 22 and the coil, by the pump 5.

The pump may be of any suitable type, may be much smaller than the main pump, and may have its own power plant, as long as it feeds the solution in. concentrated form directly to the coil, by-passing the main pump altogether.

However, we prefer the arrangement illustrated in the drawing, in which the pump is shown as a diaphragm pump comprising a housingv divided by the diaphragm. 4! into two chainbers 42' and 43. The chamber 43 is connected,

through a pipe 44, to the pump chamber of the main pump 4 so as to be operated by the latter for alternate suction and compression strokes. With a common diaphragm employed and a pipe connection as shown, the pressure developed by the diaphragm pump will be considerably less than that of the main pump, and also less than that in the discharge pipe 11. In order to make the discharge of the solution effective, therefore, it is desirable to connect the pipe 48 on the low pressure side of the metering valve 22.

The chamber 42 is connected to the solution tank 3 by means of a suction pipe 45 having a metering valve 46 and a pump intake valve 41. It is connected to pipe 17 through pipe 48 having a delivery valve 49 and an air dome 50.

Thus the concentrated solution is pumped directly into the coil without passing through the main pump, and any return flow of the diluted solution to the main pump is prevented by the check valve 2|.

The exact quantity to be pumped by the two pumps may be regulated by the two separate metering valves 22 and 46.

We claim:

1. In a cleaning machine of the character described, a coil, a tank for holding water, a second tank for holding a solution in concentrated form, a conduit connecting the water tank and the coil and having a high-pressure pump for pumping water into the coil, a valve in said conduit near the coil to deliver Water thereto at reduced pressure, a second conduit connecting the solution tank and the first conduit and having an auxiliary pump for pumping solution into the first conduit ina separate path, the auxiliary pump comprising a housing having a member reciprocable therein to divide the housing into a pump chamber and an opposing pressure chamber, and a third conduit connecting the pump chamber of the first pump and the pressure chamber of the auxiliary pump so as to cause pressures in the first pump to operate the auxiliary pump at reduced pressure, the second conduit connecting into the first conduit on the low pressure side of the valve whereby the pressure in the first conduit may be reduced and the pressure in the auxiliary pump increased to render the feeding of solution by tne auxiliary pump operative.

2. In a cleaning machine of the character described, a coil, a tank for holding water, a sec- 0nd tank for holding a solution in concentrated form, a conduit connecting the water tank and the coil and having a high-pressure pump for pumping water into the coil, a second conduit connecting the solution tank and the first conduit near the coil and having an auxiliary pump for pumping solution into the first conduit in a separate path, the auxiliary pump comprising a housing having a member reciprocable therein to divide the housing into a pump chamber and an opposing pressure chamber, a third conduit connecting the pump chamber of the first pump and the pressure chamber of the auxiliary pump so as to cause pressifi'e in the first pump to operate the auxiliary pump, and a valve in the discharge end of the first conduit upstream of the second conduit connection operable to restrict said conduit and to divert pressure from the high-pressure pump through the third conduit to the auxiliary pump for balancing pressures at the discharge ends of the first and second conduits.

JOB F. MALSBARY. WALTER W. TAYLOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 417,045 Kendrick Dec, 10, 1889 417,034 Hyatt Dec. 10, 1889 2,295,228 Malsbary et a1. -Sept. 8, 1942 

